It goes without saying that Facebook has the responsibility to protect a huge number of users—900 million to be exact. But how, exactly, does it go about doing that? The Verge has an interesting look at the behind-the-scenes hidden security measures that are routine for the social network, but that we don't often think about. It seems to be looking out for the average user, though what Facebook is doing with your data itself is a completely different story.

One of the ways Facebook protects you is by keeping tabs on your username and password. It scans sites like PasteBin weekly to make sure hackers aren't dumping people's credentials.

Another measure Facebook takes is stripping every user of their referral URL when they click one of the two trillion links posted to Facebook every day. In other words, when you click a link on Facebook that takes you to an ESPN article, ESPN cannot see what Facebook page referred you to its site, and instead sees something like "facebook.com/l.php?u=http%3A%2F%2F." These "sanitized" URLs prevent external websites from using personal information against you.

Facebook also keeps a watchful eye on bad practices referred to as "likejacking" and "clickjacking." If it suspects something is actually spam, it will give present you with a pop up that asks you if you really want to Like it before you actually hit the button.

Additionally, Malware is an obvious concern, and Facebook has a page that identifies renegade sites. But if you've been infected, Facebook will set you up with McAfee's Scan and Repair software.

When someone friends you on Facebook, that request doesn't always get through to your inbox. Facebook employs a complex algorithm to decide the likelihood that you know somebody, and whether or not to push through a friend request or file it as spam inside your "See All Friend Requests" folder. In real life, this would be like the government stopping random people from approaching you in a public place and saying hello. If these people message you, their messages will go to your Other Messages folder, a place most people don't explore.

Facebook definitely has a responsibility to its users, and now that it's public, it's got a serious financial obligation to hold onto them, which means security is an obvious concern. Which means it has to keep those hundreds of millions of users coming back, and to do that, it has to make them feel safe. And though Facebook is protecting you from outside threats, you also have to wonder who is protecting you from Facebook itself. [The Verge]